progenitor

In genealogy, a progenitor (rarer: primogenitor) is the founder (sometimes one that is legendary) of a family, line of descent, gens, clan, tribe, noble house, or ethnic group. Genealogy (commonly known as family history) understands a progenitor to be the earliest recorded ancestor of a consanguineous family group of descendants.

Progenitors are sometimes used to describe the status of a genealogical research project, or in order to compare the availability of genealogical data in different times and places. Often, progenitors are implied to be patrilineal. If a patrilineal dynasty is considered, each such dynasty has exactly one progenitor.